Composite structures and materials are frequently used in aerospace and other applications. Various components may be bonded together to form a composite structure. In aerospace applications, bonds between structural components generally are required to be of a known and certifiable strength. Bond strength can be tested in various ways. For example, in one known method for non-destructive testing, a laser burst is used to apply a shock load to a bonded joint in a structure. Measurements of surface motions of the structure resulting from the shock load are used to measure the strength of the bond. When a laser burst is used to apply a shock load to a material, an acoustic pulse typically starts with non-uniform intensity and spreads out into the material, approaching a spherical wavefront after a short distance. Accordingly, measurement of the results of such a pulse may have limited precision and resolution.